The present invention relates to radio telephone communication network of the type composed of a central station, at least two relay stations operating in the same radio channel and a plurality of substations.
In a prior art network of this type, the decision to establish a radio telephone connection from a certain substation can be indicated by transmitting from that substation a certain calling signal which is generally received simultaneously by a plurality of relay stations. Each relay station has an evaluator which has an evaluation period that is characteristic for the respective relay station. The evaluation periods of the evaluators in the relay stations are thus staggered in time. This has the inevitable result that the transmission of a calling signal from any substation must be at least as long as the longest evaluation duration of all evaluators in the relay stations of the radio telephone network.
Aside from the relatively long transmitting time required for a calling signal, this procedure also has the drawback that a change of location of a mobile substation during transmission of a calling signal will prevent evaluation in the relay stations from being performed with sufficient dependability.
A further drawback of prior art radio telephone networks is that in a case where a mobile substation is disposed in the vicinity of a relay station having an evaluator with a relatively short evaluation duration, the central station is unable to cause the relay station to switch through the radio telephone connection by way of a selective calling signal before receipt of the relatively long calling signal is completed.
Finally, the prior art radio telephone network has the further drawback that it cannot prevent the relay stations which the central station does not call by their characteristic selective calling signals from transmitting their identification signals to the central station although the central station already has called one relay station with its selective calling signal.